ABSTRACT
Classi©cation. Trevisan1 established the genus Leptotrichia in 1879 to distinguish Šlamentous microorganisms in the oral cavity from free-living Šlamentous Leptothrix species. The major metabolic end product of Leptotrichia,2 lactic acid, separates it from other Šlamentous bacteria, Fusobacterium and Bacteroides.3
